Small-object feeder for blister-packaging machine

ABSTRACT

An apparatus for filling small objects into upwardly open blisters of a strip moving in a transport direction and formed with an array of the blisters has a feeder formed by a carrier or base plate juxtaposed with the strip and formed with an array of throughgoing holes aligned with the pockets of the strip and respective tubes joined seamlessly to the plate at the holes and extending upward from the plate.

FIELD OF THE INVENTION

The present invention relates to a small-object feeder. More particularly this invention concerns such a feeder for a blister-packaging machine.

BACKGROUND OF THE INVENTION

In the packaging of, for example, pharmaceuticals a foil strip is thermoformed to have an array of upwardly open pockets or blisters. This strip is moved continuously or in steps through a filling station where one small object, typically a pill, is dropped into each blister. Such a machine is described in U.S. Pat. No. 5,737,902.

The small-object feeder typically comprises a base plate that is oriented horizontally in the filling station immediately above, if not in actual contact with the upper surface of, the passing blister strip. This base plate has an array of holes corresponding to the array of blisters on the strip and is provided with a fill tube extending vertically upward from the upper face of the base plate. Another device feeds the small objects into the tubes and allows them to drop one at a time from the end thereof synchronously while the strip moves past in strips. With a continuously moving blister strip, the feeder can be reciprocated in its travel direction so that a number of pills are dropped during its downstream synchronous movement, and the tubes refill during the upstream return stroke. With a stepped blister strip, the feeder is stationary.

When strip format changes, it is necessary to change out the feeder. With pharmaceuticals one must then get the feeder perfectly clean so that no residue of one drug ends up adhering to another drug.

Such cleaning invariably entails disassembling the feeder, that is separating the tubes from the base plate because the joint where the tubes join the base plate is particularly likely to foul, filling with particles of whatever pharmaceutical is passing through it. This is a laborious and expensive process that adds considerably to the changeover costs moving a filling machine from one format to another.

OBJECTS OF THE INVENTION

It is therefore an object of the present invention to provide an improved small-object feeder for blister-packaging machine.

Another object is the provision of such an improved small-object feeder for blister-packaging machine that overcomes the above-given disadvantages, in particular that is simple to clean.

SUMMARY OF THE INVENTION

An apparatus for filling small objects into upwardly open blisters of a strip moving in a transport direction and formed with an array of the blisters has a feeder formed according to the invention by a carrier or base plate juxtaposed with the strip and formed with an array of throughgoing holes aligned with the pockets of the strip and respective tubes joined seamlessly to the plate at the holes and extending upward from the plate.

Thus there are no joints in which residue may get stuck so that there is no requirement of having to separate the filling tubes and the filling tube carrier from each other completely, and in fact such separation would even be counterproductive. Since situations exist in which up to 180 filling tubes are assigned to one filling tube carrier plate, a significant amount of work is saved, which leads to a time and cost advantage whenever the feeder of the filling station of a thermoforming machine must be changed.

According to the invention the filling tubes and the filling tube carrier are embodied unitarily as one piece as a monolithic filling tube block. In this embodiment, the seam-free construction has advantages over the entire service life of the monolithic filling tube block without requiring any special fittings or seals.

The manufacture of such a feeder is eased when the filling tubes have ends joined to the carrier or base plate, it being in principle also possible, however, that the filling-tube base plate is positioned at a distance from the free end of the filling tubes, thus providing options for the user in order to adjust the feeder to the environmental requirements, usually the filling station of the thermoforming machine.

It has proven purposeful that at least one aperture or cutout is formed in each of the filling tubes. These cutouts can be used for sorting, buffering, separating, and depositing the small objects.

It should be emphasized that in accordance with the invention the seamless joints between the filling tubes and base plate be made in a particularly simple manner by means of an embodiment as one piece. It is also possible that the separately manufactured filling-tube base plate and the filling tubes are permanently connected to each other by means of joining technology, thus, for example, with a filling tube base plate of a certain material, filling tubes made of the same or a different material are formed in an injection-molding process. This also makes it possible for the base plate and the filling tubes to be fabricated of different materials. In addition seats may be formed in the base plate for separate supplementary filling tubes.

BRIEF DESCRIPTION OF THE DRAWING

The above and other objects, features, and advantages will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1 is a perspective view of a feeding system according to the invention; and

FIG. 2 is a larger-scale view of the feeder subassembly of the system of FIG. 1.

SPECIFIC DESCRIPTION

As seen in the drawing a feeder as used in a filling station of a thermoforming/packaging machine serves to load small objects into the blisters of a packaging strip S formed in a thermoforming station. To this end the feeder serves for the controlled simultaneous filling of these small objects O into the blisters B of the blister strip S that are arrayed in rows extending longitudinally and transversely of its feed direction D laterally arranged on a surface and parallel to the blister strip direction, for which purpose the feeder has a plurality of filling tubes 1 that are integrated in a filling tube base plate 2.

Joints 3 between of the filling tubes 1 and the base plate 2 are seamless and smooth, formed in the illustrated embodiment making the filling tubes 1 and the base plate 2 as one piece as a monolithic filling tube block 4. To this end FIGS. 1 and 2 show the filling tubes 1 have lower ends directly joined to the base plate 2. It is also possible to position the base plate 2 is possible at a spacing to the free ends of the filling tubes 1. The drawing illustrates that a total of two cutouts 5 are formed in each of the filling tubes 1 in order to adjust feed gates inside the tubes 1 in order to be able to perform a targeted separation and dropping of the small objects O in this manner. 

1. In an apparatus for filling small objects into upwardly open blisters of a strip moving in a transport direction and formed with an array of the blisters, a feeder comprising: a base plate juxtaposed with the strip and formed with an array of throughgoing holes aligned with the pockets of the strip; and respective tubes joined seamlessly to the plate at the holes and extending upward from the plate.
 2. The feeder defined in claim 1 wherein the tubes and plate are unitarily formed with one another.
 3. The feeder defined in claim 1 wherein lower ends of the tubes are joined seamlessly to the base plate.
 4. The feeder defined in claim 1 wherein the tubes have free ends spaced from the plate.
 5. The feeder defined in claim 1 wherein each tube is elongated and is formed with a transversely open cutout, whereby a respective blocking element can engage through the cutout into each tube to control small-object movement therethrough.
 6. The feeder defined in claim 1 wherein the tubes are permanently fixed on the base plate.
 7. The feeder defined in claim 6 wherein the tubes and base plate are made of different materials. 